Fix a minor typo.
@@ -24,7 +24,7 @@ By default, the ID values in the file are validated for uniqueness,
using an in-memory set. This may cause
memory usage issues for large input files, and may be inappropriate
for some files that legitimately contain duplicate records.
-The --verify-id-unique=false optin may be used to disable this check.
+The --verify-id-unique=false option may be used to disable this check.
## Usage
