Among the following groups of numbers, only the two numbers with the common factor 1 are () A. 13 and 91b. 26 and 18C. 9 and 85

Among the following groups of numbers, only the two numbers with the common factor 1 are () A. 13 and 91b. 26 and 18C. 9 and 85


A. Because 91 is a multiple of 13, in addition to 1, there are other qualitative factors 13, which are not in line with the meaning of the question B, 26 and 18, and there are other qualitative factors 2 besides 1, which are not in line with the meaning of the question; C, 9 and 85, which only have the common factor 1, are in line with the meaning of the question