Answer:
?
Explanation:
It is the "?" character. When we type in the ? in the regular expression, then it means that it will be replaced by a single character. And when we type *, then we mean there can be multiple, and any number of characters. And this is what is meant by these two wildcard characters. Hence, the correct option here is ?.
Example: ?op can be top, pop, etc, and we can see here that, ? is replaced by only one character each time.
