The answer is c because when it's an inequality, x=4 that means that you need to put it in a numberline and since the numbers to your left will always be less than 4 the shaded part is on the right.
The standard form of equation for the sin function is y = Asin(Bx-C) where A is amplitude, Period is 2π/B, and the phase shift is equal to Bx-C set to zero. C is then obtained in this equation.
For given problem: A is equal to 2, period=2π/B=2π/1=2π, where B is equal to 1. Period then is equal to A. 2pi
Well they don't get to go on holiday for two weeks only one week.