A wind brace is to be provided between two columns spaced at 5 m, at an inclination of 30° with the horizontal, to resist a tension of 320 kN developed by a wind force. The effective area required will be nearly (considering 150 N/mm2 as a relevant factor)
1
1670 mm2
2
1640 mm2
3
1600 mm2
4
1570 mm2