answer will be e^-5 which is option (C)
limx->infinity{(1-3/x)^x /(1+2/x)^x}
=e^-3/e^2
=e^-5 (we know that lim x->infinity(1+a/x)^x = e^a)
u can see formula:
check http://www.pioneermathematics.com/some-important-limits-formula.html
This problem is reducible to 1^{infinity } form after it can be solved very easily as shown below :