Critical Reasoning

Raisins are made by drying grapes in the sun.
Although some of the sugar in the grapes is
caramelized in the process, nothing is added.
Moreover, the only thing removed from the grapes is
the water that evaporates during the drying, and
water contains no calories or nutrients. The fact that
raisins contain more iron per calorie than grapes do is
thus puzzling.
Which one of the following, if true, most helps to
explain why raisins contain more iron per calorie
than do grapes?
(A) Since grapes are bigger than raisins, it takes
several bunches of grapes to provide the
same amount of iron as a handful of raisins
does.
(B) Caramelized sugar cannot be digested, so its
calories do not count toward the calorie
content of raisins.
(C) The body can absorb iron and other nutrients
more quickly from grapes than from raisins
because of the relatively high water content
of grapes.
(D) Raisins, but not grapes, are available yearround,
so many people get a greater share of
their yearly iron intake from raisins than from
grapes.
(E) Raisins are often eaten in combination with
other iron-containing foods, while grapes are
usually eaten by themselves.

Here we need to find why the iron content per calorie is more in raisins than in grapes.

We know that some of the sugar of the grapes gets caramelized in raisins and the water of the grape gets evaporated.

Now, let us go by the options:

A) Incorrect. This doesn't explain why raisins have more iron per calorie. Although grapes are bigger but as per the question, only water is lost and water has no calories, so this is not proper explanation.

B) Correct. We do know that some of the sugar of grapes gets caramelized in raisins. This option says that the caramelized sugar cannot be digested and so does not count in calorie content of raisins. So, effective calories present in raisins get reduced. Since, iron in raisins and grapes both remain the same, the iron per calorie gets increased for a raisin.

C) Out of scope

D) Out of context

E) Out of context again.

Hence, B!