Which of the classifications for humans means that we have a hollow nerve chord?
a) class
b) kingdom
c) order
d) phylum

Phylum  

Explanation:

A notochord can be defined as the beginning to the backbone which is primitive. It appears in the embryos as a flexible rod which is made from the germ layer called as mesoderm.

It is one of the 3 layers that is found in the body. These layers are ectoderm, endoderm and mesoderm.

Notochords are only found in the phylum chordata. This phylum belongs a group of animals which includes human.

i think so it’s will be b yes i believe its

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.