This depends on what kind of person you are.
Exam MLC just has a new sylluabus. The majority of people including me sitting on May 10th, 2012 felt the exam was unfair. You may want to go to
Actuarialoutpost to read their dissatisfication toward this sitting. If you want to risk that the next sitting will be easier to compensate us, then you may go ahead.
Exam C was ranked the most difficult exam out of those five preliminaries in the past. However, some people who passed all exam P, FM, MFE, C thought that this MLC May sitting was not easier than or may be even beyond exam C.