If x4y5z is exactly divisible by 9, then the least value of (x + y + z) is

(a) 3

(b) 6

(c) 9

(d) 0

$\because$ x4y5z is exactly divisible by 9

$\therefore$ The sure of its digits must be divisible by 9

$\therefore$ x + 4 + y + 5 + z or 9 + (x + y + z) must be divisible by 9

$\therefore$ Least value of x + y + z = 0 as 9 + 0 = 9 is divisible by 9 (d)