please answer the question within 30 minutes. make sure the answer and reasons are explained in very detailed manner with reasons as in why thw option is right and why other options are wrong. answer should not be copied from somewhere else i will give negative ratings for sure. make sure the answer is very detailed.

Signals to would-be challengers can be given by a. creating colloborative relationships with other industry leaders to block new entrants b. parrying the strategic thrusts of strong competitors c. maintaining secrecy about the firm's market share goals d. lobbying government regulators to reduce barriers to new entrants e. raising prices or adjusting terms of sale to sustain profits even during price war