Answer: Correct
This is a sentence written with the third person singular él (he), which is the subject el niño (the boy).
In addition, the spanish verb leer (to read) is conjugated in Preterite Imperfect Indicative as leía (read).
It is important to note this verbal tense is used in Spanish (castilian) to express courses of past actions whose beginning and end are not specified.
This means the action of "reading" performed by the boy is indicated as something in process, without defining whether it was completed or not.
Also, this sentence has the basic configuration of a spanish sentence, which is similar to english:
Subject + verb + complement
Now, in english the sentence is:
The boy read the book