Quick little question : )
how many possible isomers of heptane are there? what are the structural differences between these isomers?

Nine isomers  

Step-by-step explanation:

There are nine isomers of heptane.

The chain lengths vary from four to nine carbon atoms.

The number of substituents on the main chain, their locations on the chain, and their identities are different in each isomer.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.