Daily Dose of Solved Questions Apr 27

What is the greatest length $x$ such that $3\frac{1}{2}\:m$ and $8\frac{3}{4}\:m$ are integral multiples of $x$ ?

$(a)$ $1\frac{1}{2}\:m$
$(b)$ $1\frac{1}{3}\:m$
$(c)$ $1\frac{1}{4}\:m$
$(d)$ $1\frac{3}{4}\:m$

CSAT Mantra