$32.$ Which of the following refining processes increases the hydrogen content of petroleum fractions?

A$)$ Catalytic cracking

B$)$ Hydrocracking

C$)$ Thermal cracking

D$)$ Alkylation

$33.$ The term "upstream" in the petroleum industry refers to:

A$)$ Refining and processing

B$)$ Distribution and retail

C$)$ Exploration and production

D$)$ Marketing and sales

$34.$ What is the significance of the "crack spread" in the petroleum industry?

A$)$ The geographic spread of oil reserves

B$)$ The difference in price between crude oil and petroleum products

C$)$ The environmental impact of oil spills

D$)$ The efficiency of cracking processes

$35.$ Which of the following is a heavy, residual oil used as a fuel for ships?

A$)$ Motor gasoline

B$)$ Aviation gasoline

C$)$ Fuel oil

D$)$ Naphtha