Arvinder received an after-tax bonus of $20,000 from his employer and he is considering the following options:

1. contributing the money to his RRSP and investing the funds in a 1-year GIC with an interest rate of 4.75%
2. applying the money to his credit card to reduce his current balance of $7,600—the credit card carries an annual interest rate of 18.5%
3. investing the money in a non-registered, equity mutual fund for one year; he anticipates the fund will generate a return of 12% this year 
4. applying the money to his $50,000 personal line of credit which carries an interest rate of 6.25%. Arvinder borrowed the money to invest in an 'R' Canada Savings Bond earning 8%.

Assuming Arvinder is in a 41.5% combined marginal tax bracket and based SOLELY on tax-efficiency, rank his options from the MOST prudent to the LEAST prudent.

a) ii, i, iii and iv

b) iv, ii, iii and i

c) ii, iv, i and iii

d) ii, iii, i and iv