Which of the following is a result of the lanthanide contraction?

1. Zr and Y have nearly the same atomic radius.

2. Zr and Zn have the same oxidation state. 

3. Zr and Hf have nearly the same atomic radius.

4. Zr and Nb have similar oxidation states.

The incorrect statement among the following is:  

The reason for lanthanoid contraction is:

1. Negligible screening effect of 'f' orbitals

2. Increasing nuclear charge

3. Decreasing nuclear charge

4. Decreasing screening effect

Actinide contraction is mainly related to:
1. Poor shielding by 5f subshell
2. Extraordinary decrement in Z_eff
3. Both (1) and (2)
4. Strong shielding by 5f subshel