判断・推量N2
〜も当然だ
it is only natural that... / no wonder...
Structure
N + も当然だ；普通形 + のも当然だ
Explanation
Indicates that the result in the first clause is only natural. Attached to nouns or dictionary-form verbs + のも当然だ.
Examples
彼が怒るのも当然だ。あんなひどいことを言ったのだから。
It's only natural that he got angry—I said something awful.
彼女が合格するのも当然だ。毎日必死に勉強していたから。
It's no wonder she passed—she studied desperately every day.
Note
Similar to のは当たり前だ and に決まっている, but stresses that the result naturally follows from the cause.