TOEFL Reading: ETS-TOEFL阅读机经 - G788414M7PJ53A25L$

According to paragraph 4, all of the following occurred when the nebula stopped contracting EXCEPT: A. Gravitational interactions between heavier elements decreased. B. Temperatures declined in the area of the inner planets. C. Some elements formed rocky masses that orbited the Sun. D. Protoplanets were formed.