The Lord here starts to tell the future of the world.
V.1-2 The disciples still thought that the great temple was to be the center of God’s dealings with His people. They did not yet know that the true temple was the Lord’s body.
V.3-5 The Lord warns that many will try to deceive the believers. Today we are seeing it as never before.
V.6-14 These refer to the first half of the tribulation period (“C” to “D” on your chart). For those who wish to go into prophecy a little more, we might mention that if you read about the 7 seals in Revelation 6, you will see the similarity to these points; wars and rumors of wars (v. 6), famine and pestilence (v. 7), false prophets (v. 11). But it is possible that these verses are an outline of that whole chapter.
V.15-31 In the middle of the 7 years of the tribulation, great changes take place. The false Messiah who has pretended to be Christ for the first 3 1/2 years, will suddenly announce who he really is — the Antichrist, against God. Then the real tribulation begins.