Step 1 (Recall definitions).
Countable nouns can be counted individually (one, two, three...).
Uncountable nouns cannot be counted directly and usually do not have a plural form.
Step 2 (Identify countable noun).
"Books" is something that can be counted (one book, two books). Therefore, "books" is countable.
Step 3 (Identify uncountable noun).
"Advice" refers to suggestions or guidance and is not counted as separate units. Therefore, "advice" is uncountable.
Step 4 (Conclusion).
Countable noun: books. Uncountable noun: advice.
\[
{\text{Countable: books; Uncountable: advice (Option (a)}}
\]