Which of the following inhibits hea development?

Signals from anterior (cranial) endoderm induce a hea-forming region in overlying splanchnic mesoderm by inducing the transcription factor NKX2.5. The signals require secretion of BMPs 2 and 4 secreted by the endoderm and lateral plate mesoderm. Concomitantly, the activity of WNT proteins (3a and 8) secreted by the neural tube, must be blocked because they normally inhibit hea development. Inhibitors (crescent and cerberus) of the WNT proteins are produced by endoderm cells immediately adjacent to hea-forming mesoderm in the anterior half of the embryo. The combination of bone morphogenetic protein (BMP) activity and WNT inhibition by crescent and cerberus causes expression of NKX2.5, the master gene for hea development. BMP expression also up regulates expression of FGF8 that is impoant for the expression of cardiac-specific proteins. Ref: Langman's embryology 11th edition Chapter 12.