*Version 1- Q14
for 99% confidence interval, the answer used triple (3) standard deviation for confidence interval. I self study the test using Schweser notes, in the book, the 99% confidence interval is X-2.58s to X+2.58s. Based on my knowledge, it should be 2.58 too, not 3.

I am wondering if i misunderstood the problem and which number is the right one.

*Version 2 -Q56
which embedded option is most benificial to a bond issuer?
B. Floor on floating rate bond.
C. Accelerated sinking fund provision

Why not B? And C sounds weird to me. It can be beneficial to bond issuer if the yield rises. but it can be not beneficial either, if the yield falls. 

*Another question---
What is the major difference between sinking fund and prepayment bonds? what about callable and refundable bonds?

You may help me with any of those questions. Thanks a lot!!!!!!