Answer : 1. "36"
Explanation :

Answer: A) 36 Explanation:   LCD is nothing but Lowest or Least Common Denominator   Here LCD of 12 and 18 means LCD of two fractions with denominators 12 and 18 respectively.   Therefore, LCM of 12 & 18 = 6 x 3 x 2 = 36     How to calculate LCD :: The lowest common denominator or least common denominator (LCD) is the least common multiple (LCM) of the denominators of a set of fractions.