'Stick' is also a verb, which means 'push into/paste' For example, 'He stuck the needle into his fingers'.
Option A - 'Stiff' is an adjective which means 'firm and hard'. However, 'stiff' is not a noun form of 'stick'. Hence, option A is incorrect.
Option C - 'Sticking' is the participle form of the verb 'stick.' As we need the adjective form of 'stick' we can't used 'sticking' here. Hence, option C is incorrect.
Option D - 'Stuck' is the past form of the verb 'stick'. We need an adjective and not a verb. Hence, option D is incorrect.
Option B - 'Sticky' is the adjective form of 'stick'. For example, 'The floor is still sticky.' Hence, option B is the correct answer.