Neville, Has a Friend Named Colin

Neville, has a friend named Colin.Colin has the same demand function for claret as Neville, namely q = .02m - 2p, where m is income and p is price.Colin's income is $7,500 and he initially had to pay a price of $40 per bottle of claret.The price of claret rose to $80.The substitution effect of the price change

A) reduced his demand by 80.
B) reduced his demand by 24.
C) increased his demand by 80.
D) reduced his demand by 136.
E) reduced his demand by 34.