TOEFL Reading: ETS-TOEFL阅读机经 - 1FW1TT4CXCLMU9TGL$

According to paragraph 4, what evidence is there that an asteroid hit Earth A. The fact that the metals nickel and chromium were found at sites around the world B. The presence in K/T boundary deposits of large amounts of a metal that is found in meteorites C. The fact that iridium amounts decreased at the same time that the Cretaceous ended and the Tertiary began D. The differences in the types of metals found in deposits in Italy, Denmark, and New Zealand