The correct answer is: E. No error
The sentence is grammatically correct. The verb “was attacked” agrees with the subject “a visitor” in number and person. The preposition “by” is used correctly to show the agent of the action. The verb “had to hospitalise” is in the past participle form, which is correct for use with the past tense verb “was attacked.”
The other options are incorrect because they contain grammatical errors. Option A is incorrect because the comma after “Yesterday” is unnecessary. Option B is incorrect because the article “the” is not needed before “park.” Option C is incorrect because the preposition “by” is not needed before “tiger.” Option D is incorrect because the verb “had to hospitalise” is in the wrong tense.