Context: Despite its relative lexical unity, the two dialectal blocks of Catalan (Eastern and Western) show some differences in word choices. Any lexical divergence within any of the two groups can be explained as an archaism. Also, usually Central Catalan acts as an innovative element.

Question: What do the two blocks of Catalan display differences in?
Answer: word choices

Question: How can you explain differences in the language groups?
Answer: as an archaism

Question: What form is innovative?
Answer: Central Catalan

Question: What are the two blocks of Catalan?
Answer: Eastern and Western

Question: What does an archaism explain?
Answer: lexical divergence

Question: As what can divergence in the groups be shown?
Answer: as an archaism

Question: How does central Catalan behave with the groups?
Answer: as an innovative element

Question: What are the two dialectical groups of Catalan?
Answer: Eastern and Western

Question: What language has a lexical unity?
Answer: Catalan