I believe it’s A
Because authors write to show a purpose of something. Not for their ego.
2nd one
For example, forests help the environment by soaking up carbon dioxide, conserving soil, and preventing flooding.
The phrase, a decent respect for the opinions of mankind, was intended to convey a respect for what mankind thinks. Opinions are biases indulged by mankind inside their thought-matrices. Mankind is the species known as Homo Sapiens Sapiens.
