Identify the INVALID C program expressions or choose "all are valid". Assume all variables are integer and non-zero. If invalid explain why.

1. A) ab+ (+a/4) B) city32+3city C) (z- (+b) *b/44) D) w-y+yx2 E) All are valid

2. A)w+abc % cba B) y%y%y-2 C) q%(q/2%q) D) ha+ha+ha E) All are valid

3. A) b/c+d-a//b B) 54+45%y C) my+mx/cx D) 2*ax-ax2-w E) All are valid

4. A) b-55%5a B) 3%3-7+b C) x130b%777 D) ba/c+-33 E) All are valid

5. A) ant+ont-int3 B) chars/-5 C) one + double D) five*5/five E) All are valid

6. A) r-_x B) c+-a%4+2 C) x-m+6-24 D) xf3r6+2 E) All are valid

7. A) v-r%yy B) p-((p-p-p)) C) no+no+no3 D) x33-1.4z E) All are valid

8. A) ant%ont B) INT-double C) three*3 D) chars/b-c E) All are valid

9. A)-x-(z-44) B) a/scanf+77 C) ha-p%24 D) xaab+-77 E) All are valid

10. A) p/q/e B) px+zz/ccc C) o-o-*p D) -6+m%x E) All are valid

11. A) p*q*r- B) a%b%c C) 2*(x+y) D) %d+5 E) All are valid

12. A) rbc4/440 B) Double-9 C) z0z-a+a%a D) c*b44p+22 E) All are valid

13. A)z-33/z+4.3 B) p**2/i/kj C) i+2-2 D) i/i-11 E) All are valid

14. A) a+b-0 B) c+-a%4 C) xm6-24 D) xf3r6+2 E) All are valid

15. A) xx+yy%zz B) z%(z%z%z)) C) ha+ha+ha D) x23-20.4 E) All are valid

16. A) 0-0-0 B) mx+bb/c C) xd-wd+2ax D) 32+45%x E) All are valid

17. A) ant+int B) one+twx C) three*3 D) four/-4 E) All are valid

18. A) -a+b-33 B)3.4%7-ab C) scanf-3/3 D) xaab+-37 E) All are valid

19. A) max3*3 B) CHAR-5 C) x0x-c+a%a D) a*abc+ E) All are valid

20. A) 3-x/z+4.3 B) a/b/cd C) x+2-2 D) x^2/x-77 E) All are valid