HOTSPOT
You are designing the search service topology for a SharePoint farm.
The design must meet the following requirements:
Search services must be fault tolerant and highly available.
Search crawls must not affect page load times.
Search queries must run at the fastest possible speed.
You need to distribute the appropriate search service roles to meet the requirements.
How should you distribute the service roles? (To answer, select the appropriate service role from each
drop-down list in the answer area.)
Answer: 
Explanation:
Query Processing and Index
Note:
* Query processing component
Analyzes incoming queries. This helps to optimize precision, recall and relevance. The queries are sent to
the index component, which returns a set of search results for the query.
* Index component
Receives the processed items from the content processing component and writes them to the search
index. This component also handles incoming queries, retrieves information from the search index and
sends back the result set to the query processing component.
* Crawl component
Crawls content sources to collect crawled properties and metadata from crawled items and sends this
information to the content processing component.