Polylactic acid is the correct answer
The freezing temperature at a normal sea level air pressure is negative 78.5 degrees.
n propene molecules == polymer (polypropene)
They are also called the noble gases or inert gases. They
are virtually unreactive towards other elements or compounds. They are found in
trace amounts in the atmosphere. Their elemental form at room temperature is
colorless, odorless and monatomic gases. They also have full octet of eight
valence electrons in their highest orbitals so they have a very little tendency
to gain or lose electrons to form ions or share electrons with other elements
in covalent bonds.