A query has grouped patients by state of residence. Each group should display the number of male patients. A value of $\text{'}2\text{'}$ in the column SEX$\_$C means male. What SQL expression returns the number of male patients per group?

T ONE OF THE FOLLOWING $(2$ PTS$)$

A$.$ CASE WHEN SEX$\_$C $=\text{'}2\text{'}$ THEN SUM$(1)$ ELSE O END

B$.$ CASE WHEN SEX$\_$C $={?}^{\text{'}}2\text{'}$ THEN COUNT $(1)$ ELSE O END

C$.$ CASE WHEN SEX$\_$C $=\text{'}2\text{'}$ THEN $1$ ELSE $0$ END $)$

D$.$ COUNT $($ CASE WHEN SEX$\_$C $=2\text{'}2$ THEN $1$ ELSE O END$)$