Regular- and extra-strength pain killers are perfect substitutes; one extra-strength tablet is equivalent to two regular-strength tablets. In each of the following cases, show graphically the effect of a compensated increase in the price of regular-strength tablets. What do you find from the size of the substitution effect resulting from the increase in price of regular strength tablets?

a) The price of Extra Strength tablet is more than twice the final price of a regular strength tablet

b) The price of an Extra Strength tablet is more than twice the initial price of a regular strength tablet, but less than twice the final price

c) The price of an extra-strength tablet is less than twice the initial price of a regular strength tablet