To understand the increase in the magnitude of linear momentum, let's first define the concepts involved:

1. Kinetic Energy: Kinetic energy is the energy possessed by an object due to its motion. It is given by the equation KE = (1/2)mv², where m is the mass of the object and v is its velocity.

2. Linear Momentum: Linear momentum is the product of an object's mass and its velocity. It is given by the equation p = mv, where p is the linear momentum, m is the mass, and v is the velocity.

Now, let's consider a body with an initial kinetic energy and linear momentum. When the kinetic energy of the body is increased by 44%, we can say the final kinetic energy is 144% of the initial kinetic energy.

Let's assume the initial kinetic energy is K and the final kinetic energy is 1.44K.

Now, we need to find the percentage increase in the magnitude of linear momentum.

Using the equation for kinetic energy, we have:

1.44K = (1/2)mv²

Dividing both sides of the equation by K, we get:

1.44 = (1/2)(v²/v₀²)

Here, v₀ represents the initial velocity and v represents the final velocity.

Simplifying the equation, we get:

2.88 = v²/v₀²

Taking the square root of both sides, we get:

√2.88 = v/v₀

Now, let's consider the equation for linear momentum:

p = mv

Since momentum is directly proportional to velocity, we can say that the magnitude of linear momentum has increased by the same factor as the velocity.

Therefore, the percentage increase in the magnitude of linear momentum is given by:

(√2.88 - 1) * 100

Calculating this value, we find that it is approximately 20%.

Hence, the correct answer is option C) 20%.