Final answer:
Workers from India migrated to Guyana in the 1800s and brought their cultural traditions and festivities with them, including Diwali.
Step-by-step explanation:
The BEST explanation for why Guyana holds large Diwali celebrations each year is B) Workers from India migrated to Guyana in the 1800s.
During the 19th century, indentured workers from India were brought to various British colonies, including Guyana, to work on the sugar plantations. These workers brought their cultural traditions and festivities with them, including Diwali. Over time, Diwali became an important cultural celebration in Guyana, reflecting the significant Indian influence in the country.