Looking at the picture showing water in 3 different states notice the box above each pictures showing how the water particles are arranged in each state in which form is for to least dense
solid
liquid
gas
all forms have the same density

Is a logical series of steps

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf   

The answer to your q it is d