Answer:
Complex.
Step-by-step explanation:
A sentence can be defined as a group of words that comprises of both a subject and predicate used to convey a logical information. Sentences are classified into three (3) main categories and these includes;
I. Simple sentence.
II. Compound sentence.
III. Complex sentence.
A complex sentence comprises of both an independent clause and a dependent clause. Therefore, a complex sentence has at least one subordinate clause.
An independent clause can be defined as a clause that expresses a complete thought while standing alone as a simple sentence and comprises of at least a subject and a verb (predicate).
Some examples of an independent clause are;
She is a wise woman.
I like her.
She read the whole novel.
Hence, the structure of the statement "As he remembered his adventures, the old man smiled." is complex.