When Is the Pipe Character, I, Used in Search Strings

Multiple Choice

When is the pipe character, I, used in search strings?

A) Before clauses. For example: stats sum(bytes) | by host Before clauses. For example: stats sum(bytes) | by host
B) Before commands. For example: | stats sum(bytes) by host Before commands. For example: | stats sum(bytes) by host
C) Before arguments. For example: stats sum| (bytes) by host Before arguments. For example: stats sum| (bytes) by host
D) Before functions. For example: stats |sum(bytes) by host Before functions. For example: stats |sum(bytes) by host