Option 1 -> Optimism means hopefulness and confidence about the future, which directly aligns with sanguinity.
Option 2 -> Skepticism refers to doubt or a questioning attitude, which is contrary to the positive nature of sanguinity.
Option 3 -> Pragmatism describes a practical, realistic approach rather than a cheerful disposition.
Option 4 -> Opulence refers to wealth and luxury, which is unrelated to emotional outlook or temperament.
Hence, Option 1: Optimism -> Sanguinity derives from the Latin "sanguineus" (relating to blood) and historically described a cheerful, hopeful temperament. It is best synonymized by optimism, which captures the same positive and confident outlook on life -> correct