Is my Reasoning Correct?

Zeke21HeEatin

Hello, I originally posted this in the comments under the question but the more I look at it I'm second guessing if my reasoning is correct. I've pasted it here with a couple alterations because I accidentally put "understand" instead of "know" in the other post. It got me to the correct answer but could someone please confirm if my reasoning is correct and if not, where I went wrong. Thank you.

59.3.19

Premises:
A := Understanding a word
B := Knowing its dictionary definition
C := Understanding the words that occur in the definition

(A →B) → (A → C)

Premises: we have an instance of people (e.g., babies) who don’t understand the words that occur in the definition.
==> C

Necessary failed, contrapose back.
==> (A →B)
which is equivalent to
A and B
In other words, it could be the case that people (e.g., babies) understand the words they’re saying even if they don’t know the word's dictionary definition.

Which matches AC (E).