I think the answer is B because it ends in ing.
The correct answer is option A. Memorizing the script.
The reason is because Gerund is verbal that ends in -ING and functions in a sentences as a noun, for example:
- Smoking.
- Writing.
- Swimming.
- Staying.
The only phrases that is accurate to the definition is the option A.
it won't let me open up the link
Explanation: