The correct options are
B The Summer Solstice occurs in the month of June in the Southern Hemisphere.
C Winter Solstice is the longest day during the month of June in the Southern Hemisphere.
D Summer Solstice is the longest day during the month of January in the Southern Hemisphere.
The Winter Solstice occurs twice a year, once in the Northern Hemisphere and once in the Southern Hemisphere. The longest night of the year is observed during the winter solistice. It occurs on 21 December in the Northern Hemisphere and on 21 June, in the Southern Hemisphere. The Summer Solstice is similar to the winter solstice. The longest day of the year is observed during the summer solistice. It occurs on 21 June in the Northern Hemisphere and on 21 December in the Southern Hemisphere.