Choose the word whose underlined part is different from the others

Mn ơi, giúp mk vs ạ. Mk cần gấp
 Choose the word whose underlined part is different from the others
1. A. talk
B. walk
C. fall
D. sale
 2. A. sometimes
B. season
C. song
D. sugar
 3. A. walked
B. worked
C. painted
D. washed
 4.A. whole
B. forest
C. role
D. fold
 5. A. bought
B. brought
C. thought
D. though