Final answer:
Hector Berlioz is best known for his programmatic orchestral works, writing on orchestration, and revising colleagues' compositions, making him the answer to the question.
Step-by-step explanation:
The composer best known for his programmatic, orchestral works, contributions on orchestration techniques, and revising the works of his colleagues is Hector Berlioz. Berlioz was a key figure of the Romantic era, and his innovative approach to orchestration, as well as his passion for creating music with a narrative element ('programmatic music'), distinguished him from his contemporaries. Among his most famous pieces is the 'Symphonie Fantastique,' which is a prime example of his trendsetting work in the field of programmatic symphonies. Moreover, Berlioz's treatise on orchestration is still referenced today by composers and conductors alike. Therefore, the correct answer to the question presented is (4) Hector Berlioz.