Task: Question Answering
Input (English): Question: If planet W and planet X have a combined mass that is half that of the combined mass of planet Y and planet Z, the gravitational force between planets Y and Z will be _____ that of W and X. 
 Option1: less than 
 Option2: greater than 
 Explanation: The greater the mass of the objects, the stronger the gravitational force of attraction between them.
Output (English): greater than