Step 1: Understand the legal maxim.
\textit{Qui facit per alium facit per se} is a fundamental maxim of agency law and vicarious liability.
It translates to "He who acts through another does the act himself.
" This means a principal (employer) is liable for the acts of their agent (employee) done in the course of employment.
Step 2: Analyze the cases.
Lloyd v.
Grace, Smith & Co.
(1912): This is the landmark case where the principle was firmly applied.
A solicitor's firm was held liable for the fraud and misappropriation committed by their managing clerk, even though the fraud was for the clerk's own benefit and not the firm's.
The House of Lords held that as long as the agent was acting within the apparent scope of his authority, the principal is liable.
This directly applies the maxim.
\textit{The Mayor of Bradford v.
Pickles (1895):} This case established that a lawful act does not become unlawful merely because it is done with a bad motive.
It is not about vicarious liability.
\textit{Hamlyn v.
Houston & Co.
(1903):} This is another case on vicarious liability, but Lloyd v.
Grace, Smith & Co.
is the more famous authority on misappropriation.
Note: The provided answer key in the source image (marking option B) is incorrect.
The maxim is about vicarious liability, while Bradford v.
Pickles is about motive.
The most fitting case among the options is (D).