Answer:
option 4, 19.47°
Explanation:
From angle A, the given side length are opposite and hypotenuse
SOH CAH TOA is
sinx = opposite / hypotenuse
cosx = adjacent / hypotenuse
tanx = opposite / adjacent
visual representation below
the given length fits the characteristic to use sin
sinA = opposite / hypotenuse
sinA = 4 / 12
common facto is 4 it becomes sinA = 1 / 3
Apply trig inverse property,
x = arcsin(1/3)
x = 19.47122°