Read the excerpt by former enslaved person Olaudah Equiano. The closeness of the place, and the heat of the climate, added to the number in the ship, which was so crowded that each had scarcely room to turn himself, almost suffocated us.

We were conducted immediately to the merchant's yard, where we were all pent up together like so many sheep in a fold [pen], without regard to sex or age.

What was an effect of Equiano speaking about his experience?

Abolitionists rallied to improve the treatment of slaves.
Slavers were enraged by the loss of lives caused by the poor conditions.
Enslaved people staged violent shipboard revolts against slave ship crews.
Politicians worked to create guidelines for transportation of enslaved people.

Abolitionists rallied to improve the treatment of slaves.

Explanation:

The given excerpt is from Olaudah Equiano's memoir "The Interesting Narrative of the Life of Olaudah Equiano" where the author/speaker details the horrors of the Middle Passage. This middle passage refers to the journey of the slaves from their homes to the new foreign lands where they will be bought and sold.

In the except, Equiano reveals the horrendous and unsanitary conditions of the journey by ship where the slaves were put together. His narrative reveals the poor condition of the transport, after which they were then taken to "the merchant's yard", kept again in a closed space irrespective of the sex or age of the persons.

This experience led many abolitionists to demand better treatment of slaves and to improve such journeys. Different abolitionist groups began spreading awareness about the condition of slaves through boycotts, public petitions, and even spreading written descriptions of such horrendous journeys and lives of enslaved people.

Thus, the correct answer is the first option.