判断char型变量ch是否为小写字母的正确表达式是（）。

A.'a' <= ch <= 'z'

B.(ch >= a) && (ch <= z)

C.(ch >= 'a') && (ch <= 'z')

D.('a' >= ch) || ('z' <= ch)

A.('a'>=cl) || ('z'<=cl)

B.(cl>=a) && (cl<=z)

C.'a'<=cl<='z'

D.(cl>='a') && (cl<='z')

A.‘A’<=ch<=‘Z’

B.(ch>=“A”)&&(ch<=“Z”)

C.(ch>=‘A’)&&(ch<=‘Z’)

D.(ch>=‘A’)AND(ch<=‘Z’)

A.‘a’<=c1<=’z’

B.(c1>=’A’)&&(c1<=’z’)

C.(‘a’>=c1)||(‘z’<=c1)

D.(c1>=’a’)&&(c1<=’z’)

A.‘a’<=c1<=’z’

B.(c1>=’A’)&&(c1<=’z’)

C.(‘a’>=c1)||(‘z’<=c1)

D.(c1>=’a’)&&(c1<=’z’)

A.switch (x + y) { ...... }

B.switch (ch + 1 ) { ...... }

C.switch ch { ...... }

D.switch (a + b ); { ...... }

A.e

B.d

C.102

D.100