diff --git a/readme.md b/readme.md
index d6e5db4..b56f128 100644
--- a/readme.md
+++ b/readme.md
@@ -58,13 +58,14 @@ main menu looks like this:
 ```
 --------BiGPairSEQ SIMULATOR--------
 ALPHA/BETA T CELL RECEPTOR MATCHING
-  USING WEIGHTED BIPARTITE GRAPHS
+  USING WEIGHTED BIPARTITE GRAPHS  
 ------------------------------------
 Please select an option:
 1) Generate a population of distinct cells
 2) Generate a sample plate of T cells
 3) Generate CDR3 alpha/beta occupancy data and overlap graph
 4) Simulate bipartite graph CDR3 alpha/beta matching (BiGpairSEQ)
+8) Options
 9) About/Acknowledgments
 0) Exit
 ```
@@ -77,18 +78,20 @@ To run the simulation, the program reads and writes 4 kinds of files:
 * Graph/Data files in binary object serialization format
 * Matching Results files in CSV format
 
-These files are often generated in sequence. To save file I/O time, the most recent instance of each of these four
-files either generated or read from disk is cached in program memory. This is especially important for Graph/Data files,
+These files are often generated in sequence. When entering filenames, it is not necessary to include the file extension
+(.csv or .ser). When reading or writing files, the program will automatically add the correct extension to any filename without one.
+
+To save file I/O time, the most recent instance of each of these four
+files either generated or read from disk can be cached in program memory. This is especially important for Graph/Data files,
 which can be several gigabytes in size. Since some simulations may require running multiple, 
-differntly-configured BiGpairSEQ matchings on the same graph, keeping the most recent graph cached drastically reduces 
-execution time. 
+differently-configured BiGpairSEQ matchings on the same graph, keeping the most recent graph cached can reduce execution time
 
-Subsequent uses of the same data file won't need to be read in again until another file of that type is used or generated.
-The program checks whether it needs to update its cached data by comparing filenames as entered by the user. On 
-encountering a new filename, the program flushes its cache and reads in the new file.
+Subsequent uses of the same data file won't need to be read in again until another file of that type is used or generated,
+or caching is turned off for that file type. The program checks whether it needs to update its cached data by comparing
+filenames as entered by the user. On encountering a new filename, the program flushes its cache and reads in the new file.
 
-When entering filenames, it is not necessary to include the file extension (.csv or .ser). When reading or
-writing files, the program will automatically add the correct extension to any filename without one. 
+The program's caching behavior can be controlled in the Options menu. By default, caching for cell sample and 
+sample plate files is OFF, and caching for graph/data files is ON.
 
 #### Cell Sample Files
 Cell Sample files consist of any number of distinct "T cells." Every cell contains