How do i activate or run a function without using events?

How do i activate a function without using events?

For example i have this.

local function A()
	--random codes
end)

local function B()
	--random codes
end)

Now, How do i make it so that when the function "A" activates, It will activate function "B".

local function A()
	--random codes

	--a code that runs or activate function B
end)

local function B()
	--random codes
end)

But, I don't wanna use something like this.

Script.Parent.Touched:Connect(B)
Script.Parent.Changed:Connect(B)

P.S if it's not possible or i'm just bad at explaining please don't dislike just tell me in the comment.