Concept:The word must have the same underlined consonant sound, which is the voiceless sound /θ/.Explanation:The consonant sound given is the voiceless dental fricative /θ/.Option A "heart" begins with /h/, not /θ/.Options B "those" and C "bathe" both contain the voiced sound /ð/, which is different.Option D "thigh" is pronounced /θaɪ/, so it contains the same consonant /θ/.Answer:D. thigh