Question:
Who was the chair of Scottish National Party in Mar, 1998?

Context:
 John Swinney is the chair of Scottish National Party from Sep, 2000 to Sep, 2004. 
 Nicola Sturgeon is the chair of Scottish National Party from Nov, 2014 to Dec, 2022. 
 Alex Salmond is the chair of Scottish National Party from Sep, 1990 to Sep, 2000.

Answer:
Alex Salmond