Concept:This is a geometric sequence, so each term is found by multiplying the previous term by a common ratio.Explanation:First term: a=−10.Common ratio: r=−1050=−5.The nth term is Tn=arn−1.For the 7th term, T7=ar7−1=ar6.Substitute a=−10 and r=−5:T7=−10(−5)6=−10×15625=−156250.Answer:The 7th term is −156250, so the correct option is C.