Final answer:
A sprig of Acacia placed in the casket is a symbolic gesture appropriate for members of the Freemasons, reflecting their beliefs in the immortality of the soul and their enduring brotherhood.
Step-by-step explanation:
The sprig of Acacia is a symbol that is typically associated with the Freemasons, a well-known fraternal organization with historical roots dating back to the stonemason guilds of medieval Europe. In the context of funerary traditions, Acacia represents purity, endurance of the soul, and immortality. Due to its symbolic significance within Freemasonry, placing a sprig of Acacia in the casket would be an appropriate honor for a deceased member of the Freemasons. It signifies their belief in the immortality of the soul and the Masonic brotherhood's enduring remembrance. None of the other options provided, such as the Rotary Club, Lions Club, or Knights of Columbus, specifically use the Acacia in this way within their rituals or symbolism.