6CO2 + 6H2O → C8H12O6 + 602 A
One compound
B.
One element and one compound
C с
Two elements
D
One element

B. One element and one compound

Explanation:

O2 is a diatomic element: "are pure elements that form molecules consisting of two atoms bonded together"

*there are 7 types of diatomic elements

and...

C8H12O6 is a compound

Chemical Compound can be described as  "a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds"

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.