Answer:
The stability of the sea cliff, rock type, etc.
Explanation:
The most significant thing which must be considered is the stability of the sea cliff, rock type, etc. because it is given in the question that the place is at a top of 50 m high sea cliff. Therefore, the cliff must be stable and strong. Moreover, this is 200 m long parallel to the coast so there will not be any difficulty in the view. Thus, only stability is the primary concern that must be considered.
