You have a column named TelephoneNumber that stores numbers as varchar(20).
You need to write a query that returns the first three characters of a telephone number.
Which expression should you use?
A. CHARINDEX(‘[0-9][0-9][0-9]’, TelephoneNumber, 3)
B. SUBSTRING(TelephoneNumber, 3, 3)
C. SUBSTRING(TelephoneNumber, 3, 1)
D. LEFT(TelephoneNumber, 3)
