Pollution in cities during the late 1800s was caused in part by horses, coal, and inadequate sewer systems.

a.
true

b.
false

Pollution in cities during the late 1800s was caused in part by horses, coal, and inadequate sew systems, which is completely true. Everything was very unhygienic during the 1800s, but people started to get healthier and cleaner as time went by.

Your answer is: A) True 

Have an amazing day!