The correct option is D Mud water
The table below gives the size of particles present in various mixtures. Mixture Size of particlesSolutionLess than 10−9 mColloid Between 10−9 - 10−6mSuspensionGreater than 10−6 m Except for suspensions, neither true solutions nor colloids have constituent particles that are big enough to be visible to our naked eyes.
Amongst the given options, only mud water is a suspension. Butter and honey are colloids while salt water is a solution.