How an alignment scoring system needs to be defined?

a) - Match: needs to be positive ; Mismatch: needs to be positive ; Space: needs to be negative
b) - Match: needs to be positive ; Mismatch: needs to be positive or zero ; Space: needs to be negative
c) - Match: are higher than mismatches ; Mismatch: are higher than spaces ; Space: are lower than mismatches
d) - Match: are lower than mismatches ; Mismatch: needs to be positive ; Space: are negative numbers
e) - none of the above

Original idea by: Guilherme de Mello Barsoti