Final answer:
Peter the Great encouraged shaving by imposing a tax on beards as part of his Westernization efforts in Russia. Hence, the correct answer is option (b).
Step-by-step explanation:
The historical figure who encouraged shaving by imposing a tax on beards was Peter the Great. To modernize Russian society, Peter the Great implemented a wide range of reforms, including adopting Western European practices. One such practice was the Western style of being clean-shaven, which was in stark contrast to the traditional long beards worn by Russian men at the time.
To promote this new ideal, Peter the Great imposed a tax on beards, requiring those who wished to keep their facial hair to pay for the privilege. This policy aimed to make the boyars (noble elites) and other members of society appear more 'European' and thus, by his standards, more 'civilized.'