Answer: Vehicle
Explanation:
In this scenario, the transmission of the pathogen that causes giardiasis occurred through a vehicle, which is a non-living intermediary, such as contaminated water from the lake.
Giardiasis is commonly spread through the ingestion of water or food contaminated with the Giardia parasite, often found in untreated water sources like lakes.
By swimming in the contaminated lake, you likely ingested the water unknowingly, allowing the parasite to enter your system and cause the infection.
This mode of transmission is classified as a vehicle transmission because the pathogen was carried by the water (the vehicle) and not through direct contact with an infected individual, indirect contact, or a vector like mosquitoes.
