A variable can store . . . . . . . . value at a time.

The correct answer is B. More than one.

A variable is a location in memory that can store a value. The value can be a number, a string, or an object. A variable can store more than one value at a time, but only one value of each type. For example, a variable can store the number 10 and the string “Hello, world!”, but it cannot store the number 10 and the object “myObject”.

Option A is incorrect because a variable can store more than one value. Option C is incorrect because a variable can store more than two values. Option D is incorrect because a variable can store more than one value of each type.