For each of the following integrals, indicate whether integration by substitution or integration by parts is more appropriate, or if neither method is appropriate. Do not evaluate the integrals.

1. $\int\,x\sin x\,dx$
A. integration by parts
B. substitution
C. neither

2. $\int\,{x\over 1 + x^{2}}\,dx$
A. substitution
B. neither
C. integration by parts

3. $\int\,x e^{x^{2}}\,dx$
A. neither
B. integration by parts
C. substitution

4. $\int\,x \cos(x^{2})\,dx$
A. integration by parts
B. neither
C. substitution

5. $\int\,{1\over\sqrt{4 x + 1}}\,dx$
A. integration by parts
B. neither
C. substitution

(Note that because this is multiple choice, you will not be able to see which parts of the problem you got correct.)