Find the prime factorization of 210.2 X 3 X 5 X 72 X 3 X 352 X 7 X 15

The answer is:  [A]:  " 2 × 3 × 5 × 7 " .
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210 = 70 * 3 ;

70 * 3 = 35 * 2 * 3 ;

35* 2* 3 = 7 * 5 * 2 * 3 ; which corresponds to "Answer choice:  [A]." .
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