Step 1: Understanding the Question: The question requires identifying the very first mineral to crystallize from a cooling silicate magma according to Bowen's Reaction Series.
Step 2: Key Concept: Bowen's Reaction Series explains the specific sequence in which minerals solidify as magma cools over time.
It consists of a discontinuous branch for ferromagnesian minerals and a continuous branch for plagioclase feldspars.
Step 3: Detailed Explanation:
In the discontinuous series, minerals crystallize in a very strict order as the temperature of the magma drops.
The sequence follows: Olivine \(\rightarrow\) Pyroxene \(\rightarrow\) Amphibole \(\rightarrow\) Biotite.
Olivine is the first to crystallize because it forms at the highest temperatures (around \(1200^\circ\ \text{C}\)).
On the other hand, minerals like Quartz, Muscovite, and Potassium Feldspar crystallize last at the lowest temperatures (around \(750^\circ\ \text{C}\)).
Therefore, Olivine is the first mineral to solidify from the cooling melt.
Step 4: Final Answer: The correct answer is Olivine.