How many mongo seed are equal to 3.50 moles of mongo seeds?

2.107 x 10^24 mongo seeds​

50 moles of many mango seeds = 2.107.10²⁴ mango

Further explanation

A mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12

While the number of moles can also be obtained by dividing the mass (in grams) with the molar mass of element or molecule

With  Avogadro's number

N = number of gas particles

No = Avogadro number (6.02.10²³)

n = number of moles

n= N/No

3.50 moles of many mango seeds are comparable to

N mango seeds= 3.5 x 6.02.10²³

N mango seeds=2.107 x 10²⁴..

the answer is definitely c.