Which of these is a semi-formal summer straw hat for men?

A boater (also straw boater, basher, skimmer, The English Panama, cady, katie, canotier, somer, sennit hat, or in Japan, can-can hat, suruken) is a semi-formal summer hat for men, which was popularised in the late 19th century and early 20th century.

It is normally made of stiff sennit straw and has a stiff flat crown and brim, typically with a solid or striped grosgrain ribbon around the crown. Boaters were derived from the canotier straw hat worn traditionally by gondoliers in the city of Venice. The Venetian canotier has a ribbon that hangs freely off the back, and they are frequently edged with a matching color ribbon. Because of this, boaters were identified with boating or sailing, hence the name. Boaters were also identified more with sporting events and universities as well.

They were also worn by women, often with hatpins to keep them in place. Nowadays they are rarely seen except at sailing or rowing events, period-related theatrical and musical performances (e.g. barbershop music) or as part of old-fashioned school uniforms. Since 1952, the straw boater hat has been part of the uniform of the Princeton University Band, notably featured on the cover of Sports Illustrated Magazine in October 1955. Recently, soft, thin straw hats with the approximate shape of a boater have been in fashion among women.