Which Bhakti saint was known for his devotion to Lord Krishna and composed many devotional songs in Braj Bhasha?

Give reason for actinides show irregularities in their electronic configuration.

Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R :

Assertion A : Size of ${\mathrm{Bk}}^{3+}$ ion is less than ${\mathrm{Np}}^{3+}$ ion.

Reason R : The above is a consequence of the lanthanide contraction.

In the light of the above statements, choose the correct answer from the options given below :

Give reason: Actinoid contraction is greater from element to element than lanthanoid contraction.