The suggested answer is B, D.
When considering props.conf attributes that impact indexing performance, LINE_BREAKER and SHOULD_LINEMERGE are critical. LINE_BREAKER is used to delimit multi-line events efficiently, providing a significant boost to processing speed. SHOULD_LINEMERGE, on the other hand, controls whether Splunk should attempt to merge lines into a single event, which can impact performance if not managed properly. REPORT is used for field extraction and does not directly impact indexing performance. While ANNOTATE_PUNCT deals with indexing punctuation, it does not significantly influence performance like the other two attributes.