(A) Certain types of steering wheels, often found in cars dating from years preceding and following 1976, were found in several abandoned cars in Ambrose.
(B) No cars manufactured after 1976 were found in Ambrose, but cars manufactured before that year were found in abundance.
(C) Most historical textbooks that focus on Kansas mention that a tornado occurred there in 1976.
(D) Bicycles with banana-shaped seats, popular in Kansas between 1976 and 1986, were found in Ambrose.
(E) A torn magazine advertisement for low-tar cigarettes that were only offered in the early 1980's was found in Ambrose.
A-->as the cars were found preceding and following, this can't support engineers' hypothesis of dating back to 1976
B-->Perfect, is only cars before 1976 are found then we are sure the dating should be 1976.
C-->it doesn't matter what historical textbooks say.
D-->this ones weakens, bycycles after 1876 were also found, which means tornado was later than 1986 rather than 1976.
E-->1980's, we don't know date for sure; so it can be 1974, 1971 or 1979 too.
Hence this is also INcorrect.
Hence B