A contraceptive method or birth control method refers to a method used to avoid pregnancy or reduce the probability of getting pregnant. From antiquity, there have been different contraceptive methods but only in the last decades, methods have been designed based on science and its effectiveness has been studied.
Because of this, nowadays there are many contraceptive methods such as pills, condom, and implants that are about 80% to 95% effective, sterilization that is a around 98% effective and natural methods that have a lower percentage of effectiveness. But the only method that has been proven as completely effective or 100% effective is abstinence because by avoiding any type of sexual intercourse it is virtually impossible an egg can be fertilized by a spermatozoid.
The correct option is A.( Lens ) The eye piece is the part of the telescope that one looks through and is the part that makes the focused light visible to the eye. The eye piece is made up of magnifying lenses.