A composition, comprising: greater than 55 to 95 weight percent of a poly(arylene ether)-polysiloxane block copolymer reaction product comprising a poly(arylene ether) homopolymer, and a poly(arylene ether)-polysiloxane block copolymer comprising a poly(arylene ether) block, and a polysiloxane block comprising, on average, 20 to 80 siloxane repeating units; wherein the poly(arylene ether)-polysiloxane block copolymer reaction product comprises 1 to 30 weight percent siloxane repeating units and 70 to 99 weight percent arylene ether repeating units; wherein the poly(arylene ether)-polysiloxane block copolymer reaction product is the product of a process comprising oxidatively copolymerizing a monomer mixture comprising a monohydric phenol and a hydroxyaryl-terminated polysiloxane; and wherein the poly(arylene ether)-polysiloxane block copolymer reaction product has a weight average molecular weight of at least 30,000 atomic mass units, measured by gel permeation chromatography against polystyrene standards; 1 to 40 weight percent of a styrenic polymer selected from the group consisting of rubber-modified polystyrenes, unhydrogenated block copolymers of an alkenyl aromatic compound and a conjugated diene, hydrogenated block copolymers of an alkenyl aromatic compound and a conjugated diene, and mixtures thereof; and 1 to 40 weight percent of a flame retardant comprising an organophosphate ester; wherein all weight percents are based on the total weight of the composition, unless a different weight basis is specified; and wherein the composition exhibits a flexural modulus of 1500 to 3,000 megapascals, measured at 23°C and a sample thickness of 3.2 millimeters in accordance with ASTMD 790-10. greater than 55 to 95 weight percent of a poly(arylene ether)-polysiloxane block copolymer reaction product comprising a poly(arylene ether) homopolymer, and a poly(arylene ether)-polysiloxane block copolymer comprising a poly(arylene ether) block, and a polysiloxane block comprising, on average, 20 to 80 siloxane repeating units; wherein the poly(arylene ether)-polysiloxane block copolymer reaction product comprises 1 to 30 weight percent siloxane repeating units and 70 to 99 weight percent arylene ether repeating units; wherein the poly(arylene ether)-polysiloxane block copolymer reaction product is the product of a process comprising oxidatively copolymerizing a monomer mixture comprising a monohydric phenol and a hydroxyaryl-terminated polysiloxane; and wherein the poly(arylene ether)-polysiloxane block copolymer reaction product has a weight average molecular weight of at least 30,000 atomic mass units, measured by gel permeation chromatography against polystyrene standards; a poly(arylene ether) homopolymer, and a poly(arylene ether)-polysiloxane block copolymer comprising a poly(arylene ether) block, and a polysiloxane block comprising, on average, 20 to 80 siloxane repeating units; a poly(arylene ether) block, and a polysiloxane block comprising, on average, 20 to 80 siloxane repeating units; wherein the poly(arylene ether)-polysiloxane block copolymer reaction product comprises 1 to 30 weight percent siloxane repeating units and 70 to 99 weight percent arylene ether repeating units; wherein the poly(arylene ether)-polysiloxane block copolymer reaction product is the product of a process comprising oxidatively copolymerizing a monomer mixture comprising a monohydric phenol and a hydroxyaryl-terminated polysiloxane; and wherein the poly(arylene ether)-polysiloxane block copolymer reaction product has a weight average molecular weight of at least 30,000 atomic mass units, measured by gel permeation chromatography against polystyrene standards; 1 to 40 weight percent of a styrenic polymer selected from the group consisting of rubber-modified polystyrenes, unhydrogenated block copolymers of an alkenyl aromatic compound and a conjugated diene, hydrogenated block copolymers of an alkenyl aromatic compound and a conjugated diene, and mixtures thereof; and 1 to 40 weight percent of a flame retardant comprising an organophosphate ester; wherein all weight percents are based on the total weight of the composition, unless a different weight basis is specified; and wherein the composition exhibits a flexural modulus of 1500 to 3,000 megapascals, measured at 23°C and a sample thickness of 3.2 millimeters in accordance with ASTMD 790-10.