U sell a CDS with MV of 0 and principal of 100,000,000 if the spread duration is 3.7 what will be the new MV if the spread drop by 50 bps (so the spread was 100 bps and now it's 50 bps)

a. +1,850,000

b. + 1,910,000

c. no change

d. -1,200,000