There are two ways to do this, first find the xpath of the element of the option then issue a click method, but this method will not work on some website which monitors mouse hover event and enable the element if the mouse is hovered over the drop down box.
Another sure way of selecting the desired option from the drop down box is to use the selenium.webdriver.support.ui.Select, then select either by value or text depends on the available element in the web application.
This example uses this link: https://the-internet.herokuapp.com/dropdown
First find out the xpath of the drop down box element.

The create a select object like this:
options = Select(driver.find_element_by_xpath('//*[@id="dropdown"]'))
from the dropdown box option element there are two options which have values 1 and 2.

Here is the example gif on how it works.

Below is the code:
from webdriver_manager.firefox import GeckoDriverManager
from selenium import webdriver
from selenium.webdriver.support.ui import Select
from time import sleep
url = "https://the-internet.herokuapp.com/dropdown"
driver = webdriver.Firefox(
executable_path=GeckoDriverManager().install()
)
# The sleep function is to get a more stablized result by purposefully wait for 5 seconds.
driver.get(url)
sleep(5)
options = Select(driver.find_element_by_xpath('//*[@id="dropdown"]'))
# Selection option 2 from dropdown box.
options.select_by_value("2")
sleep(5)
options.select_by_value("1")
sleep(5)
driver.close()