Inspect the query: Mysql> SELECT count (emp_no) FROM titles WHERE title = `senior staff'; How can this query be optimized?

Question

Exhibit

Options

• AThe query need an index on the emp-no column.
• BThe query cannot be optimized as an index is already used.
• CThe query needs an index that includes the title column.
• DThe query cannot be optimized as count () must read all rows.

• A
  13% (6)
• B
  78% (36)
• C
  2% (1)
• D
  7% (3)

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