How many hydrogens are bonded to the carbons with the arrows pointing to them?

Question

Quizplus · Accepted Answer

The arrows pointing to the carbons indicate that they are double bonded to an oxygen atom, which means there is no hydrogen directly bonded to those carbons. However, each of those carbons is also bonded to two other carbons (one on each side), and each of those carbons is bonded to one hydrogen. Therefore, each of the carbons with arrows pointing to them is indirectly bonded to two hydrogens, for a total of four hydrogens between the two carbons. The correct choice is B, which indicates that carbon 1 has 0 hydrogens bonded directly to it and carbon 2 has 2 hydrogens bonded directly to it.

How Many Hydrogens Are Bonded to the Carbons with the Arrows