Explanation

A simple sentence consists of a subject and a predicate and expresses a complete thought without any dependent clauses. In the given options, we need to identify which sentence fits this definition.

Option A, "I know the place where he lives," includes a dependent clause ("where he lives") that adds extra information, making it a complex sentence.

Option B, "It is the place where he lives," also contains a dependent clause, making it complex as well.

Option D, "I know this place as he lives here," has a dependent clause ("as he lives here") that modifies the main clause and thus fails to be a simple sentence.

Option C, "I know the place of his living," has a clear subject ("I") and a verb ("know"), followed by a complete thought without any dependent clauses. The phrase "of his living" functions as a complement, but does not introduce any additional clauses. Therefore, it maintains the integrity of a simple sentence.

Thus, the correct choice is C, as it is the only option that qualifies as a simple sentence.