AIEEE 2002 Chemistry Solved Paper

Refer table from Q.No : 70
Here Ce+3,Pm+3,Yb+3 are from lanthanide series.
La+3 atomic number is 57 . This is a d block element but all the property of La is similar to lanthanides. It is present before Ce.
As we know in lanthanides the radius of elements decreases from left to right of periodic table.
So, order will be La+3>Ce+3>Pm+3>Yb+3