Which statement is true? A. sound waves and light waves travel at the same speed
B. sound waves and light waves do not travel
C. sound waves travel faster than light waves
D. sound waves travel slower than light waves

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