Translation:That watermelon is fresh.
Also wondering how the correct answer, (presence of 很 is not represented with an antecedent in the translation), is apparent. I'm guessing it is the speaker's intention to add emphasis, but in this type of exercise, the speaker says everything with flat affect. Why would translating 很 be wrong?
Sorry we can't say "that" unless we ate some watermelon... If I'm able to eat a watermelon the fruit shouldn't be far from me (my mouth).. "That" is far from me "This" I close to me. If I'm on the market buying a watermelon I could ask this question but the sentence here isn't a question
So this sentence should be like: 这个西瓜很新鲜