Is the answers C
D should be ans, bro i don't know any trick, what i did is that i learned the elements and then i observed there was a pattern among the elements. You can see the table given in ncert (d&f block )
In an easy way you can check options as you know lawrencium is the last element in actinoids and it has full filled f orbital ,so answer goes to C and D ,and i have never seen an element having 7p something ..
Oh sorry please ignore post 2.i was looking at it in opposite way. @Achyut_2020is right
Bro maybe my way be difficult for you . I have learned whole periodic table and i have just a rough idea about elements where they are placed. So as you know in d block difference in atomic number changes from 18,32,32 and tantalum lies in the group where vanadium lies so i just just add up these differences to each element from 3d series till i get 73 . And by drwaing rows and columns i count . Maybe another easy way exists but i found this one most easy .