For Passage B, what is the main idea in para 1?

A、It describe the problems found by the contractor after reading the tender documents and on-site inspection.

B、It the problems found by the owner after reading the tender documents and on-site inspection.

C、It describe the problems found by the buyer after reading the tender documents and on-site inspection.

D、It describe the problems found by the clients after reading the tender documents and on-site inspection.