Evaluate the following postfix expressions. some of them may be ill-formed expressions-in that case, identify the appropriate error message (e. g., too many operands, too few operands).

a. 1 2 3 4 5 + + +

b. 1 2 + + 5

c. 1 2 * 5 6 *

d. / 23 * 87

d. 4567 234 / 45372 231 * + 34526 342 / + 0 *

2pointswho was mikhail gorbachev? oa. a russian leader who opposed a coupob. a polish leader who founded the labor union "solidarityoc. a soviet leader who called for a closer relationship with the unitedstates, economic reform, and a more open societyd. a soviet leader who called for more oppression in the soviet union