The number of binary string types among the following is . . . . . . . .

BINARY, VARBINARY, BLOB, CHAR

This question asks about data types in MySQL that can store binary data. Let's break down each option:
BINARY: This data type stores fixed-length binary strings. It's designed to hold raw data.
VARBINARY: This data type stores variable-length binary strings. It's flexible and can store different lengths of binary data.
BLOB: This data type stores large binary objects (BLOBs). It's ideal for images, audio, or other large files.
CHAR: This data type stores fixed-length character strings. It's not meant for binary data.
Therefore, the correct answer is Option C: 3.
The three data types that can store binary strings are:
* BINARY
* VARBINARY
* BLOB