The above figure is a Cu-Ni phase diagram. Based on this information, answer the following: (c) When an alloy system with a composition of 16wt%Ni84wt% Cu at A is cooled to a temperature at B, a solid-liquid mixture will be formed. The amount of the solid phase present at B approximately is? \begin{tabular}{l} 33.3wt% \\ \hline 50wt% \\ \hline 44.8wt% \\ \hline 77.7wt% \end{tabular}