The motive behind Shahjahan’s Balkh campaign was to

(a)

secure a friendly ruler in Balkh and Badakshan which bordered Kabul

(b)

conquer Samarqand and Farghana, the Mughal homelands

(c)

fix the Mughal frontier on the ‘scientific line’, the Amu Daria

(d)

expand the Mughal Empire beyond the sub-continent