Please find the below attached question and give the answer properly.

3. In order to increase sales from the normal level of Rs 2.4 lakh per annum, the marketing manager submits a proposal for liberalising credit policy as under: Normal sales, Rs 2.4 lakh, Normal credit period, 30 days Proposed increase in credit period beyond normal 30 days Increase in normal sales 15 Rs 12,000 30 18,000 45 21,000 60 24,000 The contribution to volume ratio is 33.33 per cent. The company expects a pre-tax return of 20 per cent on investment. Evaluate the above 4 alternatives and advise the management (assume 360 days a year)