Indicate the option that is different from the rest:

Let's check the positional alphabet shifts for each option:
* QUSR: $\text{Q}(17)\stackrel{+4}{\to }\text{U}(21)\stackrel{-2}{\to }\text{S}(19)\stackrel{-1}{\to }\text{R}(18)$ (Pattern: $+4,-2,-1$)
* BFDC: $\text{B}(2)\stackrel{+4}{\to }\text{F}(6)\stackrel{-2}{\to }\text{D}(4)\stackrel{-1}{\to }\text{C}(3)$ (Pattern: $+4,-2,-1$)
* VZXW: $\text{V}(22)\stackrel{+4}{\to }\text{Z}(26)\stackrel{-2}{\to }\text{X}(24)\stackrel{-1}{\to }\text{W}(23)$ (Pattern: $+4,-2,-1$)
* KPML: $\text{K}(11)\stackrel{+5}{\to }\text{P}(16)\stackrel{-3}{\to }\text{M}(13)\stackrel{-1}{\to }\text{L}(12)$ (Pattern: $+5,-3,-1$)

Option A (KPML) violates the consistent $+4,-2,-1$ rule followed by the other three options.