For each of the following statements, say whether it is true or false, and give a reason for your answer. assume for each of the statements that if person a knows person b, then b also knows a. (a) the number of people at a party that know an odd number of other people at the party must always be even. (b) the number of people at a party for which the number of other people at the party that they don’t know is odd, must always be even. (c) the number of people at a party that know an even number of other people at the party must always be even. (d) it is possible that no two persons at a party know the same number of other people at the party.