As per Newton's II law we know that

here we know that

so here we will have

so here if we need to increase the acceleration we need to increase the applied force while on increasing the mass or on increasing the friction force the acceleration will decrease.
So here correct answer will be
<em>A) force on the object.</em>
-- 6 people all trying to push a car out of snow
-- a Tug-o-War with 30 people of different sizes pulling on each end of the rope
-- you and your sister both pulling on the same doll (or Transformer)
-- lifting a book up from the table to a high shelf
taking a book down from a high shelf to the table
(one force is you; another force is gravity)
-- grabbing your big dog by his collar and trying to bring him inside
-- three people at the table all grab the ketchup bottle at the same time
Answer:
Nucleus And electron cloud
Explanation:
Hope this helps