Call option premium is $0.70

Step-by-step explanation

Let P be Par value of bond

Then;

P= (P*4.30% +$100.50)/(1+5%)

  => P(1+5%)= P*4.30% +$100.50

    => P+ 5%P= 4.30%P+$100.50

       => P+ 5%P -4.30%P= $100.50

         => P+0.70%P= $100.50

           => P(1+0.007)= $100.50

P= $100.50/1.007

  = $99.80

Now;

Call option premium= Call price - Par value (P)

                                  = $100.50 - $99.80

                                  = $0.70