Consider the Following Linear Programming Model This Problem Violates Which of the Following Assumptions?
A)certainty
B)proportionality

Multiple Choice

Consider the following linear programming model: $$\begin{array} { l } \text { Max } \quad \mathrm { X } _ { 1 } ^ { 2 } + \mathrm { X } _ { 2 } + 3 \mathrm { X } _ { 3 } \\\text { Subject to: } \\\qquad \begin{array} { l } \mathrm { X } _ { 1 } + \mathrm { X } _ { 2 } \leq 3 \\\mathrm { X } _ { 1 } + \mathrm { X } _ { 2 } \leq 1 \\\mathrm { X } _ { 1 } , \mathrm { X } _ { 2 } \geq 0\end{array}\end{array}$$
This problem violates which of the following assumptions?

A) certainty
B) proportionality
C) divisibility
D) linearity
E) integrality