# Quiz

+ The table creation statement is as follows. Which of the following queries will be used for indexing `idx_abc` ? (Please select 2)
```
CREATE TABLE t (
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
a INT NOT NULL,
b INT NOT NULL,
c INT NOT NULL,
d INT NOT NULL,
key idx_abc (a, b, c)
);
```
  + `A.select * from t where c = 4 and a = 100 and b < 99;`  
  + `B.select * from t where c = 100 and b = 99;`  
  + `C.select a, b, c, d from t;` 
  + `D.select a, b from t;` 

------------------------------------------------------------
A, D