Answer:
Available Options are :
A <b>
B <l>
C <body>
D <small>
Ans : A <b>
Step-by-step explanation:
Normally AD and BC are written in bold letters.
for example : The terms anno Domini (AD) and before Christ (BC).
Within available option the best option to choose is <b>
The <body> element used to define the document body.
The <small> tag used to defines smaller text
But, the best option to choose is in case if they are using the HTML5 then html <time> element will be used to display BC date and AD dates.
for ex : <time datetime="-314-07-01"
calendar="Ancient Roman">1 July 314 BC</time>