Final answer:
SCORE, SBA, and SBDC are the sources that offer no-cost consulting and low-cost training to those planning a business, whereas Chambers of Commerce focus more on networking and advocacy.
Step-by-step explanation:
The sources of assistance that can provide no-cost business consulting and low-cost training for those who are planning a business include the Service Corp of Retired Executives (SCORE), the Small Business Administration (SBA), and the Small Business Development Center (SBDC). These organizations offer a wealth of resources for new business owners and entrepreneurs including mentorship, business workshops, and guidance through the formalities of starting a business. While the Chamber of Commerce is valuable for networking and advocacy, it typically does not provide consulting and training services for free or at low cost as SCORE, SBA, and SBDC do.