The word "Pentecost" comes from the Greek word pentekoste, which means "fiftieth." It refers to the Jewish festival celebrated fifty days after Passover, also known as the Feast of Weeks (Shavuot in Hebrew). In the Old Testament, this feast marked the end of the grain harvest and was one of the three major pilgrimage festivals when Jews travelled to Jerusalem (Deuteronomy 16:16).
The counting of fifty days begins from the day after the Sabbath following Passover (Leviticus 23:15-16). In the Christian context, Pentecost gained its most famous significance from the event recorded in Acts 2, when the Holy Spirit descended upon the apostles fifty days after the Passover during which Jesus was crucified. This is why the answer is specifically fifty days after Passover, not a different number or a count from Easter.
The other options are numerically incorrect. Forty days after Passover would place it before the Ascension (Jesus ascended forty days after His resurrection). Thirty days and sixty days after Easter do not correspond to any established biblical festival or the etymology of the word Pentecost.
