Final answer:
The Sniper Heart at Tier 1 adds an additional Sniper and grants a Tristana to your team, with no changes made in the 12/8/21 update.
Step-by-step explanation:
The effect of obtaining a Sniper Heart at Tier 1 is that your team counts as having 1 additional Sniper, and it grants a Tristana. According to the update mentioned with the date 12/8/21, there was no change to the effect of Sniper Heart at Tier 1. Therefore, the correct answer is C) The effect of Sniper Heart remains the same; there was no change on 12/8/21.