Here are some words translated from an artificial language.
I. moolokarn means blue sky
II. wilkospadi means bicycle race
III. moolowilko means blue bicycle

Which word could mean "racecar"?

From wilkospadi, you can determine that wilko means bicicyle and spadi means race. Therefore, the first part of the word that means racecar should begin with spadi. That limits your choices to b and d. Choice b, spadiwilko, is incorrect because we have already determined that wilkomeans bicycle. Therefore, the answer must be choice d, spadivolo.