Oxidizing agents readily accept electrons and get reduced. Let's consider the common oxidation states of the given lanthanides:
La and Lu: These lanthanides predominantly exist in the +3 oxidation state and are not strong oxidizing agents.
Eu and Yb: These lanthanides exhibit +2 and +3 oxidation states. Eu2+ and Yb2+ are reducing agents (they tend to lose electrons and get oxidized).
Therefore, only Ce4+ and Tb4+ from the given options are good oxidizing agents.
Given below are two statements:
Statement (I): The first ionization energy of Pb is greater than that of Sn.
Statement (II): The first ionization energy of Ge is greater than that of Si.
In light of the above statements, choose the correct answer from the options given below:
The product (A) formed in the following reaction sequence is:

A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is : 
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
The current passing through the battery in the given circuit, is: 
Given below are two statements:
Statement I: The primary source of energy in an ecosystem is solar energy.
Statement II: The rate of production of organic matter during photosynthesis in an ecosystem is called net primary productivity (NPP).
In light of the above statements, choose the most appropriate answer from the options given below: