Anastasia recently bought a brand$-$new warehouse. She has negotiated for a $30-$year mortgage loan for $80\%$ of the R$2600000$ purchase price in order to finance the transaction. The monthly payment on this loan will be R$11000.$ What is the effective annual rate on this loan?

a$.$

$4,98\%$

b$.$

$6,50\%$

c$.$

$2,52\%$

d$.$

$5,46\%$