Question on Common Probability Distribution

CFA Level I Quant
#1

Please help me understand the reason for the answer of the following question which is the 29th question on the pg - 244 in the Schweser Notes June-Dec 2018 :

Portfolio A has a safety-first ratio of 1.3 with a threshold return of 2%. What is the shortfall risk for a threshold return of 2% ?

A. 9.68%

B.40.3%

C.90.3%

Answer - A

What is the reason for this answer ?

#2

P(z < −1.3) = 0.0968.

#3

Was the negative sign missing in the question? Or would the safety ratio always be negative? I remember the ratio being positive most of the time.