The correct option is A Gradual
The word 'abrupt' refers to being sudden and unexpected.
Option A, gradual refers to taking place or progressing slowly or by degrees.
Option B, rough refers to having an uneven or irregular surface.
Option C, sharp refers to having an edge or pint that is able to cut or piece something.
Option D, hurried refers to being rushed or being in a hurry.
Thus, according to the meaning, the word 'gradual' is the opposite of the word 'abrupt'.