Answer:The correct answer is: 'only mass remains constant
'.
Explanation;
Mass of an object is defined as a measure of the amount of matter contained in that object.It is usually measured in grams or in kilograms. It never changes in an situation, remains constant through the space.
Weight is defined as force exerted by the gravity on the object.It is measured in Newtons and calculated by using formula :
Weight= Mass × (Acceleration due to gravity) = mg
It is force which depends upon gravity.The value weight changes if the gravity varies.Hence, not a constant quantity.
From the given options the correct option is: 'only mass remains constant'.