Explanation:

Correct answer is (c). "Hardly - when" are the correlative conjunctions, which are always used together. Thus, use of where in the sentence is incorrect and needs to be replaced.
Secondly, use of the preposition 'into' is incorrect. 'Into' means inside, which is irrelevant to the context. The correct preposition is 'onto' which means to and absolutely goes well with the context. Correct sentence- There has hardly been a day in eight years when I haven’t been inspired to walk out onto my porch to capture an unusual call or species. Hence option C is correct.