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# Hull 182.3 vs Hull 181.5

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182.3. Assume a one-year American call option (C) and a one-year American put option (P) both have a strike price (K) of $51.00 when the price of a non-dividend-paying stock (S) is$50.00. The riskless rate is 5.0%. What are the lower bounds, respectively, of the American call and American put?

a. C >= 0, P >= 0
b. C >= 0, P >= $1.00 c. C >=$1.49, P >= 0
d. C >= $1.49, P >=$1.00<--answer

Im abit confused with the below formulas

C>=S(0) - K * exp(-rT)
P >= K - S(0)

and

S(o)-K=<C-P=<S(0)-K*exp(-rT)

When is one prefered over the other?
If i do the above question using the C-P, i end up with
-1=<C-P=<1.5
However the ans is d, which fits all
What is wrong here?C=0 and p=0 definitely fits and is the lowest

The C-P formula was used in 181.5 to calculate the lower bounds