A participle is a form of verb that ends in -ing and is used as an adjective or verb. In the given sentence, 'walking' is a present participle. The sentence is in simple present tense, 'likes' is the simple present tense of the verb 'like'. Hence option A is correct. The formulation of the simple present tense is subject (She) + verb in its base form (likes) + object (walking). Option B is incorrect because the statement is not in past tense, when the verb 'like' is conjugated in past tense, the verb form is 'liked'. Option C is incorrect because the sentence is not in the future tense, the simple future form of 'like' is 'will like'. Option D is incorrect because the present continuous form of 'like' is 'liking', whereas 'likes' in the sentence is in simple present tense.