Analysis of a "currency linked" investment

I have the option to make the following investment of $1 million:

a) 1 m in SGD deposit : 2.9%pa (interest : $2,383 per month )
b) 1 m in USD deposit @ 1.53 = USD 653,594 @ 4.9%pa (interest: USD 2632 per month )
c) currency-linked investment: 1 million SGD/ USD : strike at 1.5240, 5% p.a. (USD 656,168, interest USD 2,696)

The interest rate between (b) and (c) is only 0.1% difference. If USD falls by 2%, I face the loss. If it gains by 2%, the bank gives me only 0.4% (difference between 1.524 and 1.53) and keeps the difference of 1.6%. I have decided NOT to buy the "currency linked" investment.

If I wish to invest in USD, it is better to take the straight forward deposit, ie (b) above. Do not invest in (c).